


Babysitting

by DoctorAlphys



Category: Undertale
Genre: Another random tag because i ran out of ideas, Babysitting gone wrong, F/F, F/M, Fluff, Foursome - F/F/F/M, More Fluff, Smut, Sorry Not Sorry
Language: English
Status: Completed
Published: 2015-12-07
Updated: 2015-12-07
Packaged: 2018-05-05 11:55:36
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,940
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5374388
Author URL: https://archiveofourown.org/users/DoctorAlphys/pseuds/DoctorAlphys
Summary: <blockquote class="userstuff">
              <p>You and Frisk were 19. Why did you need a baby sitter? (Feel free to leave any criticism in the comments! It helps me out a lot as I am sort of new to writing.)</p>
            </blockquote>





	Babysitting

You aren’t sure how it started, but hell...you weren’t complaining.

It was just another normal day on the surface. It’s been 11 years since you destroyed the barrier, freeing all the monsters. It’s been 10 years since Frisk took Toriel and Asgore back to the Underground to retrieve you... At first you were reluctant, saying you would probably just turn back into a flower at any given moment, but she wouldn’t take no for an answer. Somehow, you never did turn back into a flower, and now you live with Your loving parents and adopted sister. You were glad to see them back together, but hated the fact that every time they went out on a date, they had to leave you with a babysitter.

Undyne was babysitting you and Frisk. (you were both 19, but your mom is really protective...) There wasn’t much to do around your house, so she decided to take you with her so she could go see how her girlfriend was doing. You and Frisk mostly just sat on the couch as Undyne flirted with Alphys while she was doing her experiments, every small poke or smooch causing the poor woman to turn a deeper shade of red. After around 30 minutes of this, you started looking at the pile of magazines on your left. Most of them were either outdated anime catalogs or sports magazines. One magazine had caught your eye. You guessed it once had a title before mysterious claw marks ripped it off. As you slowly turned the pages, you realized what you found...

Holy shit..Did you just find a porn magazine?

You had looked up for a quick second to check if anyone was looking at you. Luckily, Frisk decided to go help Alphys by tickling Undyne’s ribs, forcing the fierce fish-woman into fits of laughter. You’re eyes traveled back to the magazine. You had recognized a few of the anime women from the days you spent with Frisk, but THOSE women had clothes... You decided that it would be best if you put it back before you get caught. You slide the scratched magazine back into the stack and relax back into the couch. Frisk eyes you from across the room, but decides to just ignore it. 

The afternoon quickly turned to night and you still haven’t gone home. Undyne came out of one of the hallways“Hey punks, your parents called. They said that they aren’t going to be home for a while, so I prepared us a sleepover! We can stay up late and watch anime, just like REAL besties would do! Fuhuhu!” Undyne motions you guys to come with her, which you do. She lead you to a spare bedroom. You guessed that it wasn’t really used all that much, but now it had a few sleeping bags, a table full of assorted snack items, a wall TV, and a small mini fridge in the corner. In one of the sleeping bags, you see Alphys in pink Mew Mew Kissy Cutie pajamas waving slowly at you two.

You and Frisk take the two sleeping bags near the mini fridge and Undyne plops herself directly next to Alphys and puts her arm around her, causing her to blush a little. “So what do you nerds want to do first?”

“W-Well I brought the entire Mew Mew Kissy Cutie box set for us to watch, that is if i-its ,uhm ,okay with you guys. Frisk? Asriel?.” Alphys looked over at you two. 

Frisk nods and signs =You know I love watching this with you= You just shrug “I mean, I guess it would be fine. I never seen it before” As soon as those words fell out of your mouth, you realized that you made a mistake. Alphys’s face gaped open with disbelief as she started rambling on about the shows entire plot. Frisk and Undyne just looked at you and giggle while the once shy lizard was passionately stating every fact from her favorite anime with great detail. After about a good 10 minutes of rambling, Undyne tapped Alphys on the shoulder and brought her back to reality. “-nd with that one kiss, she basically sa- Y-yeah Undyne? O-oh...oh geez, I...I spoiled the entire plot didn’t I...heh” She looks away shyly.

Undyne grabs Alphys’s chin with her hand and gives her a reassuring kiss “It’s okay babe, I’m sure Asriel would still LOVE to see the show, right?” Undyne then turns to you and gives you a “you-better-say-yes-or-you-will-have-a-bad-time” face. Shoving the sudden feeling of fear down into your chest, you nod enthusiastically. Alphys smiles and then walks over to the TV to prepare the DVD player. You all got into comfortable positions to watch the show, Alphys sitting in Undyne’s lap, Undyne’s arms draped over Alphys’s shoulders and chin resting on her head. You were leaning up against the wall with Frisk’s head slowly sinking into your shoulder....she seems content. Alphys clicks a button on her cellphone, starting the show. 

The intro was like any regular anime. An overly sexualized woman in super revealing clothes dancing to overly happy music in a language you didn’t understand. It then went on with the basic plot of a super cool hero deciding that they wants to be the greatest and most well known fighter ever, but the super evil dude bro people don’t want that to happen, so they send really overly complicated fighters to kill the hero. But due to plot reasons, the hero always manages to defeat the bad guy. and then they become the greatest and most well know fighter ever....man no wonder Frisk stopped watching anime with you.

Around the middle of the first episode, you got up to get something to drink from the fridge, gently tapping Frisk on the shoulder to warn her that you were getting up so she wouldn’t just fall over when you moved away. The fridge was full of different branded sodas and energy drinks. One can caught your attention though, It was black with a green M on it. The label said “Monster” energy drink. You decided that it would be fun to try it out, so you grabbed a can and headed back to return to your seat. As you go to sit back down, you look over at the couple sitting on the other side of the room. Undyne was slowly kissing Alphys down her neck, causing the small lizard monster to squirm and blush. You chuckle to yourself as you relax back into your spot. Frisk immediately leans back into you as if you never got up.

After around 3 episodes or so, you start hearing noises coming from the other side of the room. You slowly turn your head just enough to see what was going on. In the darkness of the room, you could see Undyne slowly caressing Alphys’s arms and sides. “U-Undyne” Alphys whispers “T-The kids are in t-the room with us...”

“Psh, Alphys they’re teenagers.” Undyne replys. Kissing her neck every few words. “It’s not like they haven’t heard Toriel and Asgore before.” She was right, there were a few nights when your parents had began to go at it. You shudder at the thought. You look down and notice Frisk was also watching them, a look of longing on their face..

“Whats up Frisk?” She turns back to you, but just shakes her head and smiles. She quickly signs (=I’m fine. They are really cute together=)

“Yeah, I guess they are kinda cute together aren’t they.”

Frisk looks at you, a small amount of blush fills her cheeks. (=I have an idea. Can you do that with me?=)

“Uhm...Frisk...We’re like brother and sister...wouldn’t that just make things awkward?.”

(=Not blood related=)

“I get that Frisk, but...”

She gives you her signature sad puppy dog eye look. She always does this when she doesn’t get what she wants. You tell her every time that it doesn’t work....and then give in after a few minutes. 

You sigh. “I-I mean, If you want me to, I guess..but...Uhm....I’ve never tried this before though.”

(=Just do what they are doing=) She smiles and, with the look of what you now realize as the look of determination, turns herself until you see her back. Shakily, you start to caress her arms with your hands. You’re lips carefully touching areas on her neck. You feel small vibrations coming off of her as you continued, at least she seemed to like it. Her legs starting to wiggle a little as you slowly kiss along her shoulder blade and up the side of her neck, your fingers still softly rubbing her arms and shoulders. You can hear both of your breaths start coming faster and your arms start inching closer and closer to her sides. Suddenly, you hear a loud moan coming from the other side of the room, breaking you two out of your trance.

You look over to see Alphys turned almost completely red, hand over her mouth, and Undyne’s hand quickly slipping out of her panties, slightly wet. Undyne looks at you, about to say something about what happened between them, but she notices you’re lips on Frisk’s neck and stares at the two of you. “What the hell are you two punks doing?!” Frisk looks down, blushing furiously. You just focus on the floor in front of you. “Ugh, you two are doing it all wrong! Here let me show you how its done.” Undyne then crosses over and takes your place. She looks at you “Watch closely” Immediately, she slowly starts to tenderly rub Frisk’s sides and arms, Softly moving her lips down her neck and onto her collarbone, causing Frisk to slightly moan and sink into Undyne a little. 

You slide up next to Alphys, who was trying to rid the blush from her face. You watched Undyne slowly start to trail her hands underneath Frisk’s shirt, slowly rubbing her stomach, and then cupping at her breasts. You shift a little to relieve some of the pressure building in you pants. During this, you accidentally bump into Alphys, who jumps a little before looking at you, confused at why you were fidgeting.

“Y-You okay Asriel? I-I can tell Undyne to stop if its b-bothering you.”

“It’s fine Alphys, Just having a slight, personal issue with....something. No need to worry.” You try to turn away to fix the bulge, but Alphys already spotted it. “Ah, I see w-whats wrong. Uhm...H-Here, I c-can help you with that.” 

She scoots over and starts to undo the button of your pants, releasing your semi-hard penis. She quickly gets to work, starting with a basic up-and-down jerking motion before going into more complex rotations and rubbings. For a lesbian cyber geek, she really knows how to handle you. You sigh a little with pleasure as Alphys starts to massage the tip. “D-Does this feel good?” You give a slight nod. Alphys smiles back. “Well, here let me try this.” She then leans over and starts to slowly revolve her tongue around the tip of your penis. With small circular motions and the occasional flick, she already has you leaking and groaning with pleasure. 

Noticing this, she then starts to stick more of the cock into her mouth. Sliding your member deeper and deeper before retracting. She continues this back and forth motion, her tongue still continuing its work on the tip. How in the hell was she so good at this? You’re breathing starts to get heavier as she goes on, her pace quickens a bit. You start slowly moving your hips upward into her mouth. You notice her other hand sliding into her pants, rubbing herself. She softly moaned into your penis, creating small vibrations along it.“Nnngh, A-Alphys, I’m getting. gaAah, c-close!” She looks up at you and smiles, or what appears to be a smile, and with one swift motion, she brings her head down fast, shoving your entire cock into her throat. This motion pushes you over the edge, releasing your load directly into Alphys’s mouth. She quickly retracts, coughing and spitting a little.

“S-Sorry Alphys, Didn’t mean to-”

“N-No it’s fine Asriel. Uhm...” She looks down a little, obviously embarrassed. “It actually was...kinda nice...

You look back to Undyne and Frisk, Both of them have taken off their clothes and were on the floor, naked, Frisk was laying down, legs spread wide open, while Undyne was bent over with her ass in the air, her face up to Frisk’s private parts. She was slowly pleasuring Frisk’s folds with her tongue while massaging her own, causing them both to gasp with pleasure. Undyne then slips one finger into Frisk, forcing her back to arch wildly with passion as her orgasm reaches its peak. Undyne, though, looked slightly sad that she couldn’t get herself to climax...She looks over at you, staring at your, now exposed, cock and looks down shyly. “Uhh...A-Asriel... Could I- um...heh...I never actually...did it with...another..guy....and I was just wondering if you would...uhh....help me with this?” She gestures at her body, blushing slightly

“Sure Undyne...” You say. She smiles wide and starts to crawl seductively towards you and straddles you’re legs. You slowly start to caress her body as she lines your cock up with her entrance. She teases you a bit, before lowering herself down onto your member, letting out a soft moan. Undyne then begins to ride you’re penis, her breast bounce with every motion. You reach up and start to massage them, causing Undyne to moan a little louder. Her thrust start getting faster and faster. “A-Ah shit! I think I’m going to-” and with one final bounce, she leans into you and cries out in pleasure, digging her fingers into your fur. You feel a small amount of pain when she nibbles a bit on your shoulder.

She slowly gets up and looks over at Alphys, who was staring at both of you, massaging herself. “Alphys, you GOT to try this.”

“U-Uhm, I don’t k-know...” She states, embarrassed that she got caught.

“Oh come on.” She walks over to Alphys, giving her a passionate kiss on the lips, before grabbing her hand and bringing her over to you. She hesitates at first, not really knowing what to expect, but with the help of Undyne, she gets herself undressed. Surprisingly, Alphys looked really beautiful. Well you guessed she always looked beautiful, but you never really noticed it. With a little more coaxing, she takes Undyne’s place, She slowly slides your cock inside of her and loudly gasps “W-Wow, This feels, really amazing...” She then turns and gives Undyne a sloppy french kiss as she starts to move up and down. 

A shadow looms above your face as you see Frisk’s head slowly peak into your vision, before kissing you on the nose. =Don’t forget about me= “I would...ah...never forget about you...ah...Frisk.” You say, making her giggle. Then she straddles your chest with her ass facing towards you. Without hesitation, you start to slide your tongue along her folds. Causing her to start pulsating with pleasure. Meanwhile, Alphys was riding your dick like a pro. She was revolving her hips in a circle while continuing the basic up and down movements. 

“A-Ah, I...I’m...I’m coming!” Alphys screams as she continues her sexual assault on your manhood. She finally stops and looks down at you, giving you a small thank you smile. Frisk leans into Alphys, grabbing her cheeks, and giving her a firm kiss on the lips. This sudden affection causes Alphys to feint into Undyne’s arms. Frisk then starts to sit herself onto your cock. Without second thought, she just slides your member right into her You look up at Frisk, her face contorting and flexing with every motion, screams of lust flow through her mouth, You begin to feel another orgasm approaching soon. You begin to thrust along with Frisk, causing her to moan louder, her hands reaching up to massage her own breasts. 

“Ngh, F-Frisk I can’t hold it in any longer!” She doesn’t seem to care though, continuing her strides, she begins to ride you faster. The walls of her vagina start to close in, pressuring your penis. “F-Fuck I’m coming!” You scream, pushing yourself deeper inside of Frisk and unloading your seed. She leans backwards and howls in pleasure as she reaches her second climax. 

As Frisk settles off of you and starts to lay down onto the floor, she starts to laugh, You all look at her for a second...and then after a couple of smirks and snorts, you were all in a huge fit of laughter. 

“Huh, We should have these sleepovers more often.” You say, winking at an obviously blushing Undyne. 

“I-I agree with Asriel.” Alphys says, her fingers slowly tapping together. She seemed to be having troubles trying to find her pajama blouse. 

You all settle back down into your original spots to watch Mew Mew Kissy Cutie again. Though, this time you slid your arm around Frisk and held her close to you. You give her a kiss on the top of her head. She looks at you, a shy smile on her face. You chuckle a little before kissing her softly on the lips. “Mom and Dad can NEVER find out about this.” She gives you a small nod and sinks deeper into your side, slowly caressing your chest.

I guess having a babysitter isn’t all that bad...


End file.
